/* roulang page: index */
:root {
      --bg-dark: #070b14;
      --bg-surface: #0c1322;
      --card-bg: rgba(16, 26, 48, 0.72);
      --border-glow: rgba(56, 189, 248, 0.18);
      --primary-blue: #2563eb;
      --neon-sky: #38bdf8;
      --text-main: #f8fafc;
      --text-sub: #94a3b8;
      --text-dim: #64748b;
    }
    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-dark);
      color: var(--text-main);
    }
    body {
      background-color: var(--bg-dark);
      overflow-x: hidden;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--border-glow);
      box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.45);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .glass-card:hover {
      border-color: rgba(56, 189, 248, 0.4);
      transform: translateY(-3px);
      box-shadow: 0 16px 40px -10px rgba(14, 165, 233, 0.2);
    }
    .btn-glow {
      background: linear-gradient(135deg, #2563eb, #0284c7);
      box-shadow: 0 0 20px rgba(37, 99, 235, 0.5);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .btn-glow:hover {
      box-shadow: 0 0 30px rgba(56, 189, 248, 0.75);
      transform: translateY(-2px);
      filter: brightness(1.1);
    }
    .btn-ghost {
      background: rgba(15, 23, 42, 0.6);
      border: 1px solid rgba(56, 189, 248, 0.3);
      backdrop-filter: blur(10px);
      transition: all 0.3s ease;
    }
    .btn-ghost:hover {
      background: rgba(56, 189, 248, 0.15);
      border-color: var(--neon-sky);
      color: #fff;
    }
    .tech-badge {
      background: rgba(37, 99, 235, 0.12);
      border: 1px solid rgba(56, 189, 248, 0.3);
      color: #7dd3fc;
    }
    .gradient-text {
      background: linear-gradient(135deg, #ffffff 20%, #7dd3fc 70%, #38bdf8 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .glow-dot {
      box-shadow: 0 0 8px #38bdf8;
    }
    .grid-pattern {
      background-size: 40px 40px;
      background-image: 
        linear-gradient(to right, rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
    }